Synthesis, characterization and alcohol oxidation properties of multi-wall carbon nanotubes functionalized with a cobalt(II) Schiff base complex

A hydroxyl functionalized cobalt(II) Schiff base complex has been covalently anchored to modified multi wall carbon nanotubes (MWNTs). The modified MWNTs have been characterized by physico-chemical and spectroscopic methods. The results suggest that the symmetrical Schiff base, N,N'-bis(4-hydroxysalicylidene)-ethylene-1,2-diamine; H-2[((OH)(2)-salen)] acts as a tetradentate N2O2 donor via the deprotonated phenolic oxygens and azomethine nitrogens. The functionalized [Co((OH)(2)-salen)]-MWNTs catalyze the oxidation of aliphatic and aromatic alcohols into the corresponding carboxylic acids and ketones in the presence of 30% H2O2 in good yields. The system is truly heterogeneous (no leaching observed) and reusable (no decrease in activity over three consecutive runs).